Devices and methods for heart valve treatment
Devices and methods for improving the function of a valve (e.g., mitral valve) by positioning an implantable device outside and adjacent the heart wall such that the device alters the shape of the heart wall acting on the valve. The implantable device may alter the shape of the heart wall acting on the valve by applying an inward force and/or by circumferential shortening (cinching). The shape change of the heart wall acting on the valve is sufficient to change the function of the valve, and may increase coaptation of the leaflets, for example, to reduce regurgitation.
This patent application claims the benefit of U.S. Provisional Patent Application No. 60/425,519, filed Nov. 12, 2002, entitled DEVICES AND METHODS FOR HEART VALVE TREATMENT to Vidlund et al., the entire disclosure of which is incorporated herein by reference (hereinafter referred to as “Vidlund et al., '519”).FIELD OF THE INVENTION
The present invention relates to devices and associated methods for treating and improving the performance of dysfunctional heart valves. More particularly, the invention relates to devices and methods that passively assist to reshape a dysfunctional heart valve to improve its performance.BACKGROUND OF THE INVENTION
Various etiologies may result in heart valve insufficiency depending upon both the particular valve as well as the underlying disease state of the patient. For instance, a congenital defect may be present resulting in poor coaptation of the valve leaflets, such as in the case of a monocusp aortic valve, for example. Valve insufficiency also may result from an infection, such as rheumatic fever, for example, which may cause a degradation of the valve leaflets. Functional regurgitation also may be present. In such cases, the valve components may be normal pathologically, yet may be unable to function properly due to changes in the surrounding environment. Examples of such changes include geometric alterations of one or more heart chambers and/or decreases in myocardial contractility. In any case, the resultant volume overload that exists as a result of an insufficient valve may increase chamber wall stress. Such an increase in stress may eventually result in a dilatory process that further exacerbates valve dysfunction and degrades cardiac efficiency.
Mitral valve regurgitation often may be driven by the functional changes described above. Alterations in the geometric relationship between valvular components may occur for numerous reasons, including events ranging from focal myocardial infarction to global ischemia of the myocardial tissue. Idiopathic dilated cardiomyopathy also may drive the evolution of functional mitral regurgitation. These disease states often lead to dilatation of the left ventricle. Such dilatation may cause papillary muscle displacement and/or dilatation of the valve annulus. As the papillary muscles move away from the valve annulus, the chordae connecting the muscles to the leaflets may become tethered. Such tethering may restrict the leaflets from closing together, either symmetrically or asymmetrically, depending on the relative degree of displacement between the papillary muscles. Moreover, as the annulus dilates in response to chamber enlargement and increased wall stress, increases in annular area and changes in annular shape may increase the degree of valve insufficiency. Annular dilatation is typically concentrated on the posterior aspect, since this aspect is directly associated with the dilating left ventricular free wall and not directly attached to the fibrous skeleton of the heart. Annular dilatation also may result in a flattening of the valve annulus from its normal saddle shape.
Alterations in functional capacity also may cause valve insufficiency. In a normally functioning heart, the mitral valve annulus contracts during systole to assist in leaflet coaptation. Reductions in annular contractility commonly observed in ischemic or idiopathic cardiomyopathy patients therefore hamper the closure of the valve. Further, in a normal heart, the papillary muscles contract during the heart cycle to assist in maintaining proper valve function. Reductions in or failure of the papillary muscle function also may contribute to valve regurgitation. This may be caused by infarction at or near the papillary muscle, ischemia, or other causes, such as idiopathic dilated cardiomyopathy, for example.
The degree of valve regurgitation may vary, especially in the case of functional insufficiency. In earlier stages of the disease, the valve may be able to compensate for geometric and/or functional changes in a resting state. However, under higher loading resulting from an increase in output requirement, the valve may become incompetent. Such incompetence may only appear during intense exercise, or alternatively may be induced by far less of an exertion, such as walking up a flight of stairs, for example.
Conventional techniques for managing mitral valve dysfunction include either surgical repair or replacement of the valve or medical management of the patient. Medical management typically applies only to early stages of mitral valve dysfunction, during which levels of regurgitation are relatively low. Such medical management tends to focus on volume reductions, such as diuresis, for example, or afterload reducers, such as vasodilators, for example.
Early attempts to surgically treat mitral valve dysfunction focused on replacement technologies. In many of these cases, the importance of preserving the native subvalvular apparatus was not fully appreciated and many patients often acquired ventricular dysfunction or failure following the surgery. Though later experience was more successful, significant limitations to valve replacement still exist. For instance, in the case of mechanical prostheses, lifelong therapy with powerful anticoagulants may be required to mitigate the thromboembolic potential of these devices. In the case of biologically derived devices, in particular those used as mitral valve replacements, the long-term durability may be limited. Mineralization induced valve failure is common within ten years, even in younger patients. Thus, the use of such devices in younger patient groups is impractical.
Another commonly employed repair technique involves the use of annuloplasty rings. These rings originally were used to stabilize a complex valve repair. Now, they are more often used alone to improve mitral valve function. An annuloplasty ring has a diameter that is less than the diameter of the enlarged valve annulus. The ring is placed in the valve annulus and the tissue of the annulus sewn or otherwise secured to the ring. This causes a reduction in the annular circumference and an increase in the leaflet coaptation area. Such rings, however, generally flatten the natural saddle shape of the valve and hinder the natural contractility of the valve annulus. This may be true even when the rings have relatively high flexibility.
To further reduce the limitations of the therapies described above, purely surgical techniques for treating valve dysfunction have evolved. Among these surgical techniques is the Alfiere stitch or so-called bowtie repair. In this surgery, a suture is placed substantially centrally across the valve orifice joining the posterior and anterior leaflets to create leaflet apposition. Another surgical technique includes plication of the posterior annular space to reduce the cross-sectional area of the valve annulus. A limitation of each of these techniques is that they typically require opening the heart to gain direct access to the valve and the valve annulus. This generally necessitates the use of cardiopulmonary bypass, which may introduce additional morbidity and mortality to the surgical procedures. Additionally, for each of these procedures, it is very difficult to evaluate the efficacy of the repair prior to the conclusion of the operation.
Due to these drawbacks, devising effective techniques that could improve valve function without the need for cardiopulmonary bypass and without requiring major remodeling of the valve may be advantageous. In particular, passive techniques to change the shape of the heart chamber and/or associated valve and reduce regurgitation while maintaining substantially normal leaflet motion may be desirable. Further, advantages may be obtained by a technique that reduces the overall time a patient is in surgery and under the influence of anesthesia. It also may be desirable to provide a technique for treating valve insufficiency that reduces the risk of bleeding associated with anticoagulation requirements of cardiopulmonary bypass. In addition, a technique that can be employed on a beating heart would allow the practitioner an opportunity to assess the efficacy of the treatment and potentially address any inadequacies without the need for additional bypass support.SUMMARY OF THE INVENTION
To address these needs, the present invention provides, in exemplary non-limiting embodiments, devices and methods for improving the function of a valve (e.g., mitral valve) by positioning an implantable device outside and adjacent the heart wall such that the device alters the shape of the heart wall acting on the valve. The implantable device may include two anchor ends with a interconnecting member connected therebetween. The anchor ends and the interconnecting member may be positioned on the outside of the heart. Optionally, a protrusion may be connected to the interconnecting member between the anchor ends. The anchor ends may be connected to the heart wall around the dysfunctional valve, and the interconnecting member may be tightened or cinched therebetween. Because the heart wall is generally curved, the act of cinching the interconnecting member between the attached anchor ends may cause the interconnecting member to apply an inward force against the heart wall acting on the dysfunctional valve, and/or may shorten the distance between the anchor ends and thus deform the heart wall inward to act on the dysfunctional valve. The inward force may act on any one of or any combination of valve structures (e.g., valve annulus, papillary muscles, etc.) and/or adjacent anatomical coronary structures. If a protrusion is utilized, it may be used to apply and focus additional force against the heart wall.BRIEF DESCRIPTION OF THE DRAWINGS
Besides the structural and procedural arrangements set forth above, the invention could include a number of other arrangements, such as those explained hereinafter. It is to be understood that both the foregoing description and the following description are exemplary. The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the invention and, together with the description, serve to explain certain principles. In the drawings,
The following detailed description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention.
The various aspects of the devices and methods described herein generally pertain to devices and methods for treating heart conditions, including, for example, dilatation, valve incompetencies, including mitral valve leakage, and other similar heart failure conditions. Each disclosed device may operate passively in that, once placed on the heart, it does not require an active stimulus, either mechanical, electrical, hydraulic, pneumatic, or otherwise, to function. Implanting one or more of the devices operates to assist in the apposition of heart valve leaflets to improve valve function.
In addition, these devices may either be placed in conjunction with other devices that, or may themselves function to, alter the shape or geometry of the heart, locally and/or globally, and thereby further increase the heart's efficiency. That is, the heart experiences an increased pumping efficiency through an alteration in its shape or geometry and concomitant reduction in stress on the heart walls, and through an improvement in valve function.
However, the devices disclosed herein for improving valve function can be “stand-alone” devices, that is, they do not necessarily have to be used in conjunction with additional devices for changing the shape of a heart chamber or otherwise reducing heart wall stress. It also is contemplated that a device for improving valve function may be placed relative to the heart without altering the shape of the chamber, and only altering the shape of the valve itself. In other words, the devices and methods described herein involve geometric reshaping of portions of the heart and treating valve incompetencies.
The devices and methods described herein offer numerous advantages over the existing treatments for various heart conditions, including valve incompetencies. The devices are relatively easy to manufacture and use, and the transluminal, transthoracic, and surgical techniques and tools for implanting the devices do not require the invasive procedures of current surgical techniques. For instance, these techniques do not require removing portions of the heart tissue, nor do they necessarily require opening the heart chamber or stopping the heart during operation. For these reasons, the techniques for implanting the devices disclosed herein also are less risky to the patient than other techniques. The less invasive nature of these techniques and tools may also allow for earlier intervention in patients with heart failure and/or valve incompetencies.
Although the methods and devices are discussed hereinafter in connection with their use for the mitral valve of the heart, these methods and devices may be used for other valves of the heart for similar purposes. One of ordinary skill in the art would understand that the use of the devices and methods described herein also could be employed for other valves of the heart. The mitral valve has been selected for illustrative purposes because a large number of the disorders occur in connection with the mitral valve.
The devices and methods described herein are discussed herein with reference to the human heart H, but may be equally applied to other animal hearts not specifically mentioned herein. For purposes of discussion and illustration, several anatomical features may be labeled as follows: left ventricle LV; right ventricle RV; left atrium LA; ventricular septum VS; right ventricular free wall RVFW; left ventricular free wall LVFW; atrioventricular groove AVG; mitral valve MV; tricuspid valve TV; aortic valve AV; pulmonary valve PV; papillary muscle PM; chordae tendeneae CT (or simply chordae); anterior leaflet AL; posterior leaflet PL; coaptation line CL; annulus AN; ascending aorta AA; thoracic aorta TA; azygos vein AZV; coronary sinus CS; cardiac vein CV; right coronary artery RCA; left anterior descending artery LAD; obtuse marginal artery OM; circumflex artery CFX; left lung LL; right lung RL; dermal layer DL; sternum ST; xiphoid XPH; diaphragm DPH; and vertebrae VRT.
General Description of Exemplary Implant Devices
With reference to
The position of the protrusion 18 may be adjusted relative to the anchor ends 12/14. To accommodate such adjustment, the interconnecting member 16 may be fixedly connected to one or both of the anchor ends 12/14 and adjustably connected to the protrusion 18. Alternatively, the interconnecting member 16 may be fixedly connected to the protrusion 18 and adjustably connected to one or both of the anchor ends 12/14. In both instances, the length of the interconnecting member 16 between the protrusion 18 and the anchor ends 12/14 may be adjusted to change the position of the protrusion 18 relative to the anchor ends 12/14.
The anchors 12/14 serve to secure the ends of the interconnecting member 16 to the heart wall. The anchors 12/14 may comprise vacuum cups with tissue piercing pins for securement as described in more detail with reference to
The interconnecting member 16 may be fixed or selectively fixed (i.e., adjustable) to each of the anchors 12/14 and/or the protrusion 18 as described above. The interconnecting member may be made fixed or adjustable using, for example, a lock pin technique as described in more detail with reference to
As an alternative to interconnecting member 16, or in conjunction with interconnecting member 16, pericardial tissue may be used to connect the anchor ends 12/14 and protrusion 18 (if used). For example, a first anchor end 12 may be fixedly secured to both the epicardium and the pericardium using an anchor device with open top and bottom surfaces as described in Vidlund et al., '519. The second anchor end 14 may be secured to epicardium, and the protrusion 18 may be secured to the pericardium (by using an anchor device for the protrusion 18). The interconnecting member 16 may be fixedly connected to the protrusion 18 and adjustably connected to the second anchor end 14 (or visa-versa) such that the position of the protrusion 18 may be adjusted (e.g., cinched) relative to the second anchor end 14. By virtue of the common pericardial connection between the first anchor 12 and the protrusion 18, cinching the interconnecting member 16 between the protrusion 18 and the second anchor 14 also causes cinching between the protrusion 18 and the first anchor 12, without requiring the interconnecting member 16 to be connected to the first anchor 12.
The interconnecting member 16 may be elongate and will normally be in tension when implanted. The interconnecting member may comprise a flexible and biocompatible multifilament braid in the form of a string or strap, for example. If a string or chord is used, for example, an atraumatic pad (as seen in
The interconnecting member 16 may be formed as described in U.S. Pat. No. 6,537,198 to Vidlund et al., the entire disclosure of which is incorporated herein by reference. In particular, the interconnecting member 16 may comprise a composite structure including an inner cable to provide mechanical integrity and an outer covering to provide biocompatibility. The inner cable of interconnecting member 16 may have a multifilament braided-cable of high performance polymeric fibers such as ultra high molecular weight polyethylene available under the trade names Spectra™ and Dyneema™, polyester available under the trade name Dacron™, or liquid crystal polymer available under the trade name Vectran™. The filaments forming the inner cable may be combined, for example, in yarn bundles of approximately 50 individual filaments, with each yarn bundle being approximately 180 denier, and two bundles may be paired together (referred to as 2-ply) and braided with approximately 16 total bundle pairs with approximately 20 to 50 picks per inch (number of linear yarn overlaps per inch).
The outer covering surrounding the inner cable of the interconnecting member 16 may provide properties that facilitate sustained implantation, and may thus be formed of a material that is biocompatible and allows for tissue ingrowth. For example, the outer covering surrounding the inner cable of the interconnecting member 16 may be made of a polyester material such as Dacron or ePTFE. If an atraumatic pad is used, it may be formed of, coated with, or covered by the same or similar material as the outer covering of the interconnecting member to promote tissue in-growth for additional anchoring effect. For example, the atraumatic pad may be formed of ePTFE which is biocompatible, promotes tissue in-growth, and conserves cross-sectional size and shape despite elongation.
The protrusion 18 may comprise a balloon, plug, or other mechanical spacer or structure, and may be fixedly or adjustably connected to the interconnecting member 16. The protrusion 18 may be centered between the anchors 12/14, or may be eccentrically positioned therebetween. One or more protrusions 18 may be used, and the protrusions may have various geometries depending on the desired allocation of forces acting on the heart wall. The protrusion 18 may be coated or covered by a tissue in-growth promoting material to secure the protrusion to the heart wall in the desired position, and the material may be highly elastic or otherwise stretchable to permit expansion of the protrusion 18. Examples of suitable materials include ePTFE and polyester knits.
Description of Exemplary Implant Positions And Functions
With reference to
The implantable device 10 may affect MV function by acting on the adjacent heart wall in several different modes. For example, in one mode of operation, the protrusion 18 (or the interconnecting member 16 if no protrusion is used) of the implantable device 10 may apply or focus an inward force against the heart wall acting on the MV. The back-up force (i.e., the substantially equal and opposite force to the inward force) may be provided by the interconnecting member 16 as fixed to the heart wall by the anchor ends 12/14, the anatomical structure behind the protrusion 18, or a combination thereof. In an alternative mode of operation, the implantable device 10 may act to cinch, compress or otherwise deform the heart wall surrounding the posterior aspect of the mitral valve MV by shortening the circumferential length thereof. In another alternative mode of operation, the implantable device 10 acts to both apply an inward force and cause circumferential shortening. In each of these modes of operation, the inward force and/or circumferential shortening may be applied throughout the cardiac cycle, or may only act during a portion of the cardiac cycle such as during systole.
The implantable device 10 may be implanted in a number of different positions, a select few of which are described herein for purposes of illustration, not necessarily limitation. Generally, the implantable device 10 may be positioned outside the epicardium of the heart wall adjacent the mitral valve MV, such as between the epicardium and pericardium, or between the pericardium and the pleural sac. Also generally, to maximize the effectiveness of the inward force, the implantable device 10 may be positioned to create a normal force against the heart wall that is generally orthogonal to the coaptation line CL formed by the leaflets PL/AL. This may be achieved, for example, by positioning the device 10 in a posterior-lateral projection of the mitral valve MV generally orthogonal to the middle tangent of the coaptation line CL as shown in
A variety of long axis and short axis positions are contemplated and the particular combination may be selected to have the desired effect. In the short axis view as seen in
To avoid compression of the coronary arteries which typically reside near the surface of the heart wall, the implantable device 10 may have relatively small contact areas selected and positioned to establish contact with the heart wall while avoiding key anatomical structures. For example, as shown in
Description of Exemplary Delivery Techniques And Approaches
The implantable device 10 may be implanted using one or a combination of various methods and approaches. Generally, these delivery methods may be utilized to implant the device 10 in the pericardial space adjacent the posterior projection of the mitral valve MV. There are a number of different approaches and techniques for positioning the implantable device 10 as such, and these generally include surgical, transluminal and transthoracic techniques. For purposes of illustration, not necessarily limitation, an anterior transthoracic (subxiphoid) approach is described in more detail with reference to
Exemplary Embodiments of Implant Devices
With reference to
As seen in
The anchors 112 and 114 may comprise a vacuum cup 120 with a tissue piercing pin 122 extending through the interior thereof. The cup 120 may be injection molded, for example, of a suitable biocompatible material such as PEEK, HDPE or PTFE, and the piercing pins 122 may be formed of stainless steel, for example. The piercing pins 122 are slidingly received in two bores disposed in the walls of the cup 120. A locking mechanism such as mating geometry between the bores and the pins may be used to lock the pins in the pierced position as shown. A port 124 in communication with the interior of the cup 120 is provided for releasable connection to an anchor catheter 400 as shown and described with reference to
Each cup 120 has a rim that conforms to the epicardial surface of the heart wall such that vacuum applied to the cup 120 by the anchor catheter 400 via port 124 draws the epicardial surface of the heart into the interior of the cup. With the epicardial tissue drawn inside the cup by the vacuum, the tissue piercing pin 122 may be advanced to pierce through the heart tissue and lock in the pierced position as shown. A lock mechanism such as illustrated in
The protrusion 118 includes a base 140, an inflatable balloon 142 mounted to the base 140, and an outer covering 144 (shown partially cut-away) extending over the balloon 142. The base 140 may be connected to a locking mechanism 160 (not visible) located on the opposite side of the balloon 142, which in turn is connected to the interconnecting member 1116. The base 140 may comprise a flexible or semi rigid polymeric material, and the balloon 142 may comprise a compliant or non-complaint polymeric material conventionally used for implantable balloons. Outer covering 144 may comprise a material that promotes tissue in-growth to provide additional anchoring stability over time. The balloon 142 may be pre-filled, or may be filled during implantation, with a liquid that may solidify (cured) over time. To facilitate inflation of the balloon 142, the interior of the balloon 142 may be in fluid communication with an inflation catheter via a lumen (not visible) extending through the locking mechanism 160 and the base 140 as described with reference to
The interconnecting member 116 may comprise two multifilament braided cables 132 and 134. One end of each cable 132 and 134 may be fixedly connected to the anchors 112 and 114, respectively, and the other ends of the cables 132 and 134 may be adjustably connected together by a locking mechanism 160 (not visible) attached to the base 140 of the protrusion 118. The cables 132 and 134 may extend through a pair of atraumatic pads 130 that are secured to the base 140 of the protrusion 118.
As seen in
Strap 230 may vary in length as a function of the length of the cable 232, and includes a plurality of pockets 234 that may be selectively filled with one or more plugs 236 to serve as the protrusion 218, or the pockets 234 may remain empty. For example, selection of the pockets 234 to fill with plugs 236 may be made apply an inward force against the heart wall while avoiding or jumping over coronary arteries residing near the surface of the heart wall. Strap 230 may comprise a woven polymeric material as polyester, and the plug 236 may comprise a solid polymeric material such as PEEK, silicone, HDPE, PTFE or ePTFE.
As seen in
Protrusion 618 may include a center rotating member 642 coupled to cross member 644 by pivot connection 646. The rotating member 642 may be rotated 90 degrees relative to cross member 644 about pivot 646 as indicated by arrows 640. The rotating member 642 may be rotated as indicated by arrows 640 between a low profile delivery configuration wherein the rotating member 642 is generally aligned with the cross member 644, and a deployed configuration wherein the rotating member 642 is generally orthogonal to the cross member 644 as shown. The rotating member 642 may be rotationally biased to the deployed configuration and may be locked in the deployed configuration. A pair of protrusions 648 may be disposed at opposite ends of the cross member 644. The rotating member 642 in addition to the protrusions 648 may function as protrusions as described previously, while the gap therebetween may be used to avoid critical anatomical structures such as coronary vasculature.
As seen in
Protrusion 718 may include a center rotating member 742 coupled to cross member 744 by pivot connection 746. The rotating member 742 may be connected to the cross member 744 by an elastic ring and may be rotated 90 degrees relative to cross member 744 about pivot 746 as indicated by arrows 740. The rotating member 742 may be rotated as indicated by arrows 740 between a low profile delivery configuration wherein the rotating member 742 is generally aligned with the cross member 744, and a deployed configuration wherein the rotating member 742 is generally orthogonal to the cross member 744 as shown. The rotating member 742 may be rotationally biased to the deployed configuration and may be locked in the deployed configuration. A pair of protrusions 748 may be disposed at opposite ends of the cross member 744. The rotating member 742 in addition to the protrusions 748 may function as protrusions as described previously, while the gap therebetween may be used to avoid critical anatomical structures such as coronary vasculature.
As seen in
Exemplary Embodiments of Delivery Devices
With reference to
The delivery catheter 300 includes a tubular shaft 310 defining an inflation lumen and two cable lumens extending therethrough. A pair of push tubes 312 extend along side the tubular shaft 310 and slidably accommodate push rods 332 and 334. The distal ends of the tubular shaft 310 and push tubes 312 are coupled to the locking mechanism 160 by a release mechanism 326 such as a threaded, pinned or other releasable connection, such as the pin mechanism illustrated in
The proximal end of the tubular shaft 310 is connected to a manifold including connectors 322 and 324 and inflation port 318. The inflation lumen of the tubular shaft 310 provides fluid communication between the interior of the balloon 142 and the inflation port 318 of the manifold 314 for connection to an inflation device (not shown) to facilitate inflation and deflation of the balloon 142. If no balloon 142 is used, the inflation lumen and associated parts may be eliminated. The cable lumens of the tubular shaft 310 accommodate the proximal portions of the cables 132 and 134 for connection to a sizing device 500 via connectors 322 and 324 as described with reference to
With additional reference to
With reference to
The anchor catheters 800 are essentially mirror constructions of each other (with the exception of split tube 813), and include a tubular shaft 810 comprising a directional catheter construction connected to a handle 850. The directional catheter shaft 810 and associated handle 850 are available from Medamicus, Inc. of Plymouth, Minn. Handle 850 generally includes a grip portion 852 and a thumb knob 854 which actuates control wires in the directional catheter shaft 810 to permit selective bi-directional lateral deflection of the distal end thereof. The directional catheter shaft 810 and associated handle 850 accommodate a push rod (not visible) extending therethrough for actuation of the tissue piercing pin 722. The push rod for the tissue piercing pin 722 may comprise a stainless steel mandrel, for example, with a distal end abutting the proximal end of the tissue piercing pin 722, and a proximal end connected to a knob 814. The directional catheter shaft 810 and associated handle 850 also accommodate a vacuum lumen (not visible) extending therethrough to define a fluid path to the interior 720 of the anchor 712/714, such that a vacuum source (not shown) may be connected to vacuum port 816 on the handle 850 to provide suction at the anchor 712/714 to facilitate stabilization and securement to the outside of the heart wall.
Each of the anchor catheters 800 also includes a side tube 812 coextending with the directional catheter shaft 810. Side tube 812 accommodates the interconnecting member 732, a push rod (not visible) for actuation of the interconnecting member piercing pin 752, and a pull wire (not visible) for release of the anchor 712/714 as described in more detail below. The interconnecting member 732 extends through the side tube 812 from a proximal port 822/824 through the anchor 712/714 to the protrusion 718. To accommodate the interconnecting member 732 during initial delivery of the implant 710, a slotted side tube 813 may be provided on one of the catheters 800.
The push rod for the interconnecting member piercing pin 752 may comprise a stainless steel mandrel, for example, with a distal end abutting the proximal end of the interconnecting member piercing pin 752, and a proximal end connected to knob 832/834. A pair of guide loops 815 may be provided distal of the side tube to guide the interconnecting member 732, and a guide tube 862/864 may be provided distal of the side tube 812 to guide the push rod for the interconnecting member piercing pin 752.
The distal end of the directional catheter shaft 810 is connected to anchor 712/714 by a releasable connection 820, which may comprise a threaded type connection or a cotter pin type connection, for example. In the illustrated embodiment, the releasable connection 820 comprises a cotter pin type connection, with the pull wire (not visible) proximally connected to pull knob 842/844, and distally extending through aligned holes (not visible) in the anchor 712/714 and in the fitting on the distal end of the directional catheter shaft 810. By pulling proximally on pull knob 842/844, the anchor 712/714 may be released from the distal end of the directional catheter shaft 810.
With reference to
To connect the cable to the inner rod or tube 518, the cable 132/134, 232, 632 or 732 is threaded through receiving tube 510, through measuring tube 514, through the inner tube 518, and placed in a retaining mechanism 520 disposed on the inner tube 518. Engagement member 512 may be connected to one of the connectors 322/324 or 822/824 on the delivery catheter, or directly to the lock mechanism 160 of device 110 or lock mechanism of device 210. With this arrangement, the inner tube 518 may be pulled proximally relative to the measuring tube 514 to apply tension to the cable and thus selectively adjust the tightness or degree of cinching of the implantable device 110/210/610/710, and/or selectively adjust the position of the protrusion relative to the anchor ends.
Exemplary Embodiments of Access Devices
With reference to
Outer tube 1100 may comprise a rigid tubular shaft 1102 formed of stainless steel, for example, having a lumen extending therethrough. A cap 1104 having an interior recess (not visible) may be connected to the distal end of the shaft 1102. A handle 1106 may be connected to a proximal end of the tubular shaft 1102 to facilitate manual manipulation. A vacuum port 1108 may be incorporated into the handle 1106 to facilitate connection to a vacuum source (not shown) for establishing a vacuum in the lumen extending through the tubular shaft 1102.
The securement tube 1200 may comprise a rigid tubular shaft 1202 formed of stainless steel, for example, having a lumen extending therethrough. An annular array of pericardium piercing pins 1204 may be disposed at the distal end of the tubular shaft 1202, and are sized to fit in the recess inside cap 1104 at the distal end of the outer tube 1100 as will be discussed in more detail with reference to
The cutter tube 1300 may comprise a rigid tubular shaft 1302 formed of stainless steel, for example, having a lumen extending therethrough. An annular cutting edge 1304 may be disposed at the distal end of the tubular shaft 1302. An annular ring 1306 may be disposed adjacent the distal end of the tubular shaft 1302 to provide a slidable fluid seal with the inside surface of the tubular shaft 1202 of the securement tube 1200. A series of vacuum holes 1308 may be provided through the side of the tubular shaft 1302 distal of the annular ring 1306 to provide a fluid path from the interior of the securement tube 1200 to the interior of the cutter tube 1300, thus permitting a vacuum to be established inside the tubular shaft 1302 of the cutter tube 1300 by application of a vacuum to vacuum port 1108. A handle 1310 may be disposed at the proximal end of the tubular shaft 1302 to facilitate manual manipulation and to act as a stop to prevent the cutter tube 1300 from advancing fully into securement tube 1200. A visualization device 1320 such as a camera or eye piece 1322 and light source 1324 may be connected to the proximal end of the tubular shaft 1302 to permit direct visualization down the lumen of the cutter tube 1300. Alternatively, an intracardiac echo device may be inserted therethrough, using vacuum for stability, to permit visualization and guidance on the epicardial surface.
With reference to
Exemplary Embodiments of Access and Delivery Methods
Generally speaking, once pericardial access is established with an access system as described with reference to
The following detailed example of a delivery method using the delivery system and implant illustrated in
To establish pericardial access, a needle may be inserted into the chest cavity below the xiphoid as generally shown in
Using the access device illustrated in
Initially, the interconnecting member may be loaded into the first anchor and anchor catheter with one side of the interconnecting member extending through the side tube and the other side of the interconnecting member extending through the slotted side tube. Before delivering the anchor, angiographic visualization of the left and/or right coronary arteries may be performed to map the locations of the critical arteries. To deliver the first anchor near the PDA as shown in
The protrusion may then be advanced along the first anchor catheter by removing one end of the interconnecting member from the slotted tube on the anchor catheter, inserting it through the protrusion and fixing the protrusion midway on the interconnecting member. A delivery tube may be placed about the protrusion to retain it in the delivery configuration, and the delivery tube with the protrusion therein may then be inserted through the access device. By pulling on the opposite end of the interconnecting member and by manipulating the delivery tube, the protrusion may be advanced until it is adjacent the first anchor.
Before delivering the second anchor near the LAD as shown in
With the first and second anchors secured to the outside of the heart wall, and the protrusion extending therebetween, the interconnecting member may be tightened or cinched using the device illustrated in
With the aid of fluoroscopy, correct anchor positioning may be verified and adequate blood flow may be confirmed in the left coronary arteries. After confirming correct positioning and adequate reduction in MVR, the interconnecting members may be secured by actuating interconnecting member piercing pins with the associated push rods, and the directional catheter shaft may be disconnected from the anchors by actuating the releasable connection with the associated pull wires.
The delivery system may then be removed, and the interconnecting members may be trimmed adjacent the anchors with a cutting device such as an elongate cautery tool. The access device may be removed and the sub-xiphoid access site may be closed using sutures.
From the foregoing, it will be apparent to those skilled in the art that the present invention provides, in exemplary non-limiting embodiments, devices and methods for improving the function of a valve (e.g., mitral valve) by positioning an implantable device outside and adjacent the heart wall such that the device applies an inward force against the heart wall or otherwise deforms the heart wall thus acting on the valve to improve leaflet coaptation. Further, those skilled in the art will recognize that the present invention may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departures in form and detail may be made without departing from the scope and spirit of the present invention as described in the appended claims.
114. A method of reducing the circumference of a mitral valve annulus comprising the steps of:
- providing a mitral valve reducing device comprising an elongate member;
- positioning the elongate member in a first position at a location adjacent the atrioventricular groove and exterior of the vasculature of the heart, wherein in the first position, the elongate member has a first radius of curvature; and
- releasing the elongate member in the.atrioventricular groove in a second position wherein in the second position the elongate member has a second radius of curvature less than the first radius of curvature so as to reduce the circumference of the mitral valve annulus.
115. The method of claim 114 wherein the step of positioning the elongate member in a first position comprises accessing and navigating the pericardial space.
116. The method of claim 114 wherein the step of releasing the elongate member in the atrioventricular groove in a second position comprises bending the elongate member from the first position into the second position.
117. The method of claim 116 wherein the step of providing an elongate member comprises providing an elongate member comprising a cinching mechanism; and wherein the step of bending the elongate member comprises actuating the cinching mechanism.
118. The method of claim 117 wherein the step of providing an elongate member comprises providing an elongate member having a preferential bending mechanism at a location along a length of the elongate member; and wherein the step of bending the elongate member comprises bending the elongate member at the location.
119. The method of claim 114 further comprising the step of increasing tissue adherence to the elongate member.
120. The method of claim 119 wherein the step of increasing tissue adherence occurs prior to releasing the elongate member in the atrioventricular groove in the second position.
121. The method of claim 119 wherein the step of increasing the tissue adherence comprises:
- providing a coating on the elongate member to cause a tissue response.
122. The method of claim 121 wherein the step of providing a coating comprises providing a coating comprising a tissue growth promoter to cause tissue growth around the elongate member.
123. A system for reducing the mitral annulus of a heart comprising:
- a mitral valve reducing device comprising: an elongate member having a first position wherein in the first position, the elongate member has a first radius of curvature, and a second position wherein in the second position the elongate member has a second radius of curvature less than the first radius of curvature; and
- a delivery system comprising: a catheter configured to access a pericardial space of a heart, adjacent an atrioventricular groove and outside of vasculature of the heart; and a mitral valve reducing device delivery member configured to place the reducing device in the atrioventricular groove.
124. The system of claim 123 wherein the mitral valve reducing device comprises a cinching mechanism; and wherein the step of bending the elongate member comprises actuating the cinching mechanism.
125. The system of claim 123 wherein the mitral valve reducing device comprises a preferential bending mechanism at a location along a length of the elongate member.
126. A mitral valve reduction device comprising:
- an elongate member having a first position wherein in the first position, the elongate member has a first radius of curvature, a second position wherein in the second position the elongate member has a second radius of curvature less than the first radius of curvature, and a bending mechanism configured to move the elongate member from the first position to the second position; and
- a coating on the elongate member, wherein the coating comprises a tissue response promoter for promoting a tissue response adjacent the elongate member.
127. The mitral valve reduction device of claim 126 wherein the coating comprises a tissue growth promoter.
128. A mitral valve reduction device comprising:
- an elongate member having a first position wherein in the first position, the elongate member has a first radius of curvature and a second position wherein in the second position the elongate member has a second radius of curvature less than the first radius of curvature; and
- an end comprising a tissue engaging element configured to engage the heart within the atrioventricular groove.
129. The mitral valve reduction device of claim 128 wherein the tissue engaging element comprises at least one finger member extending from the end of the elongate member.
130. The mitral valve reduction device of claim 128 further comprising:
- a bending mechanism configured to move the elongate member from the first position to the second position.
International Classification: A61F 2/24 (20060101);